Damper for locomotive-superheaters.



i N. T. McKEE. DAMPER FOR LOCOMOTIVE SUPERHEATEN.

APPLICATION FILED SEPT. 14, 1915. v v 1,167,5Q8. r Patented Jan.11,1916.

2 SHEETSSHEET 2.

ATTORNEYS rinrrnn snares Parana canton.

NEAL TRIMBLE McKEE, OF YONKERS, NEW YORK, ASSIGNOR T0 LOCOMOTIVE SUPER-HEATER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

Specification of Letters Patent.

Patented Jan. 11, 1916.

Application filed September 14, 1915. Serial No. 50,570.

To all whom it may concern:

Be it known that I, NEAL TRIMBLE Mo- KEE, a citizen of the UnitedStates, and resident-of Yonkers, county of Westchester, and State of NewYork, have invented a new and useful Improvement in Dampers forLocomotiveSuperheaters, of which the following is a specification.

My invention relates to dampers and means for operating the same inconnection with locomotives having superheaters of the fire tube type;more particularly my invention relates to dampers for locomotives of thecharacter specified which are to be used for switching or otherintermittent service where the steam is frequently cut OE and on, andwhere the demands of the service require that power be furnished forperiods which are, relatively short and frequent' Among the objects ofmy invention are the following: To automatically protect the superheaterpipes or elements from being overheated and thereby damaged or burnedout; to provide a damper which will automatically perform the justindicated function and at the same time permit the hot gases to passthrough the fire tubes which contain the superheater elements at alltimes except when steam is cut off from the main engine cylinders andthe blower is on; and to provide a means for automatically shutting offthe supply of steam to the blower during such periods as the main enginecylinders are being supplied with steam.

In carrying out my invention I employ, in connection with a casingsurrounding the ends of the superheater pipes where they emerge from thefire or smoke tubes at the froii't tube'sheet, a damper in said casingwhich" is connected with a steam piston in a suitable cylihd'er or anequiyalent, said piston or its equivalent'being controlled by the jointaction of steam leading from the blower connection and steam leadingfrom the steam chest or main steam pipe, so that when the engine isrunning under steam, the damper will be opened whether the blower be onor not, while, when steam is cut off and the blower is on, the damperwill be closed; when steam is cut off from the steam chest and theblower is also cut oil, the

damper is preferably arranged to be open.'

In the prior art are to be found automatic devices comprising a damperarranged to control the flow of furnace gases through the fire tubes,said damper being actuated by a piston in a steam cylinder connectedwith the steam supply to the engine cylinders and controlled by theengine throttle. In such arrangements, however, the damper is closedwhenever the steam supply is cut off so that when the engine is standingidle or drifting wlthout steam the superheater pipes are not receivingany increase of heat units.

In a patent to Hoilmann dated December 12, 1912, and No. 1,011,197 thereis disclosed an improved type of the damper regulating device justmentioned in which the superheater pipes have hot gases flowing overthenr at all times except when the bloweris on, whether or not steam isbeing supplied to the engine cylinders, thereby maintaining a higheraverage of superheat and securing a resultant greater fuel etliciency.Other advantages are also secured by the Hoffmann invention.Adisadvantage, however, of the Hoffmann arrangement is that, while theblower is turned on and steam is being supplied to the engine cylinders,no fire gases will pass through the fire tubes containing thesuperheater pipes and consequently the steam will not be superheated.

My invention will be better understood by referring to the accompanyingdrawings in which Figure 1 represents a central vertical longitudinalsection, part elevation, through a locomotive boiler with superheaterand a damper (in closed position) with preferred form of regulatingdevice according to my invention; Fig. 2 represents an elevation,-

part section, of the damper (in open position) and regulating device ofFig. 1; Fig. 3 represents, diagrammatically, a modified form of myimproved damper and regulating device; Fig. 4c is a representation,similar to Fig. 3, of another modification of my invention; and Fig. 5represents, similarly to Fig. 3, still another modification of myinvention.

In the drawings a certain number of fire tubes, 1, contain superheaterpipes, 2, the ends of which terminate'i'n a steam collector casing 3. Asshown, th e fire tubes which contain the superheater pipes areconsiderably larger in diameter than the ordinary locomotive fire tube,but I-rhay, if I choose,

use superheaterfire tubes of usual diameter,

run-ll either making the superheater 'pipes themselves smaller or usinga smaller number of such pipes to each fire tube.

Surrounding the entire group of superheated pipe ends, as they emergefrom the fire tubes, is a sheet iron casing, 4:, in the lower part ofwhich is arranged a damper, 5, extending substantially across theboiler. Fig. 1 shows the damper in closed position and Fi 2 in openposition. When the dam.- per is closed, the casing acts as a battlemeans which completely cuts oil the flow of furnace gases through thefire tubes, 1, containing the superheater pipes, and when the damper isopened these gases have their maximum freedom of flow. The damper, 5,

is pivoted upon a longitudinal axis 6 and has rigidly attached to it, bya short arm, 7, a counterweight, S, the position of arm andcounterweight being so related to the clan per that the counterweighttends to hold the v damper normally open. The blower pipe, 9, is joinedby a T connection, 10, to a pipe, 11, leading to the main steam supplyand has, somewhere in its length, a control cock (not shown) by whichthe steam flowing to the blower pipe may be turned on or off. Runningforward from the 'l', 10, is a steam pipe, 12, leading to acylinder,'13, in which is a piston, 1%, having a piston rod, 15. Thispiston rod is pivoted at, 16, to one end of alink, 17, the outer end ofwhich is pivoted at, 18, to a crank arm, 19, fixed upon the damper axis,6; The cylinder, 13, may be conveniently aiiixed to the outside 01 theboiler. The other end of the cylinder, 13, is connected by pipe, 20, tothe live steam supply outside of the main throttle. As shown, theconnection is made to the main steam pipe, but this connection mightequally well go to the steam chest or to some other point capable ofaffording a supply of live steam.

The operation oi my invention isas fol lows: When the locomotive isstationary, with main throttle closed, but with blower on, the blowersteam pressure will move the piston toward the damper axis, raising thecounterweight and closing the damper, so as to shut off the flow of firegases over the superheater elements. It, now, the throttle be opened,the steam pressures on the two sides of the piston will be equal to oneanother and the counterweight will become effective to open the damper;it is not necessary to shut off the steam from the blower. It throttlebe closed and blower oli the counterweight will keep the damper open.

In the forms shown in Figs. 3, 4 and 5 the counterweight is omitted. InFig. 3 there are two alined steam cylinders having their pistons, 14L,142, connected. by a rod 21. The damper crank arm, 19, is pivoted in anopen slot formed in this piston rod between the cylinders. One cylinder,13, is larger than.

the other, 13 the outer end of the larger cylinder being connected tothe main steam pipe and the outer end of the smaller cylinder beingconnected to the blower. -With the engine standing idle and mainthrottle closed, but with blower on, the pistons will be moved to theleft under the pressure of the blower steam and the damper closed. It,now, the throttle be opened the pistons will be moved to the right andthe damper opened owing to the larger area ofthe piston which is actedupon by the main steam supply.

The modification shown in Fig. 4 is identical' with that of Fig. 3,except that the blower nozzle, 9, opens from the smaller cylinder nearthe innerend thereof. The counterweight 8 (shown dotted) may or may notbe used, as desired. With the engine standing still, main throttleclosed, and cab blower valve opened the pistons will be moved to theleft, the damper closed, and the blower steam supplied to the smallercylinder will pass out'ot the connecting pipe to theblower nozzle. Whenthe main throttie is opened, with blower on, the pistons will be movedto the right, owing to the larger area of the piston acted upon by themain steam supply, the damper will be opened, and the supply of steam tothe blower nozzle cut off automatically. Vith main steam supply andblower supply both cut oil, the damper will be closed by thecounterweight, 8, if the same be used.

In the form shown in Fig. 5 there are two cylinders of equal diametermounted one above the other. The respective piston rods project from theright of the cylinders and are connected by links, 17, to opposite endsof the lever crank arm, 19, fixed to the axis, 6, of the damper. Thedamper axis is so determined that the part of the lever crank armjoining it to the upper piston is longer than the lever arm joining itto the lower piston. The left hand end of the lower cylinder isconnected to the blower and the left hand end of the upper piston to themain steam pipe. Whenthe engine is standing still, with blower on, thelower piston is moved to the right and the damper closed. lVith the mainthrottle open and steam supplied to both upper and lower cylinders fromthe main steam sup ply'and from the blower respectively, the same steampressure will be active on the two pistons but,owing to the longer leverarm acted upon by the piston of the upper cylinder, the pressure tendingto move the upper piston to the right will overcome the pressure opposedto .it and the damper will be opened.

Instead of having the cylinders in Figs 3 and 4t alined I may, it Iprefer, have them set at an angle with independent piston rods acting onthe same crank arm.

Referring to the construction shown in Fig. 4, it is clear that, if thecounterweight be used, the arrangement will operate equally well whetherthe two cylinders be of the same diameter or have unequal diameter asshown.

Various other changes of arrangement and in detail may be made withinthe spirit of my invention and the scope of the following claims:

1. In a locomotive provided with a blower and a superheater of the classdescribed, the combination with the superheatertubes, of battle meansincluding a damper in the path of the furnace gases, steam actuatedmeans operatively attached to the damper, a steam connection between themain steam pipe and the steam actuated means tending to open the damperand a steam connection between the blower and the steam actuated meanstending to close the damper.

2 In a locomotive provided with a blower and a superheater of the classdescribed, the combination with the superh'eater tubes, of battle meansincluding a damper in the path of the furnace gases, steam actuatedmeans operatively attached to the damper, a steam connection between themain steam pipe and the steam actuated means tending to open the damper,a steam connection between the blower .and the steam actuated meanstending to close the damper, and a counterweight fixed to the damper andtending to open the damper.

3. In a locomotive provided with a blower and a superheater of the classdescribed, the combination with the superheater tubes, of ballie meansincluding a damper in the path of the furnace gases, steam actuatedmeans attached to the damper and a steam connection between said steamactuated means and the main steam pipe and between said means and theblower said connections being arranged to produce oppositely actingpressures upon said steam actuated means.

4. In a locomotive provided with a blower and a superheater of the classdescribed, the combination with the superheater tubes, of baffle meansincluding a damper in the path of the furnace gases, a pair of pistonmechanisms operatively attached to said damper, a steam connectionbetween one piston mechanism and the main steam pipe, and steamconnections at opposite ends of the other piston mechanism to blowernozzle and blower steam supply respectively, the connection to blowersteam supply being arranged so as to act oppositely, as to the damper,to the connection from the other piston mechanism to the main steampipe.

5. In a locomotive provided with a blower and a superheater of the classdescribed, the combination, with the superheater tubes, of bafile meansincluding a damper in the path of the furnace gases, steam actuatedmeans operatively attached to the damper, a steam connection betweensaid steam actuated means and the main steam pipe tending to open thedamper, a steam connection be"- tween the steam actuated means and theblower steam supply, and a steam connection going from the steamactuated means to the blower nozzle said last named connec tion beingopen or closed according to the position of the steam actuated means.

6. In a locomotive provided with a blower and a superheater of the classdescribed, the combination, with the superheater tubes, of battle meansincluding a damper in the path of the furnace gases, steam actuatedmeans operatively attached to the damper to open or close the same, ablower, a steam connection to said blower, and means controlled by thesteam actuated means for automatically opening or closing said blowersteam connection according as the damper is closed or open.

In testimony whereof I have hereunto set m hand.

3 NEAL TRIMBLE MGKEE.

